Speaker Cable VS Instrument Cable

[Lifeofsobriety]

So this is kind of a noob question.

What is the difference between a speaker cable and an instrument cable.

Heres the issue:

Me and my buddy got together for a jam the other day. A few days later he realizes his speaker cable is missing. I look through my cables and alas there is an extra one there. The issue is the look exactly the same. A generic black cable with silver ends.... We arn't sure how to tell the difference. If we were to guess the wrong cable and use the instrument cable to go from his amp to his cab could it damage the amp? and is there any way to really tell the difference?

Thanks

Dan

[adamcbest]

the amp's output transformer will burn up!! big difference between the cables. never use an instrument cable as a speaker cable. although i think you can use a speaker cable as an instrument without harming anything.

[jb4674]

the easiest way to tell is to unscreww the cover of the connector for each cable so you can see the difference. At that point, label your friend's speaker cable so both of you know what it is.

Jimmy

[Lifeofsobriety]

Well we opened them and one of them is sealed... I compared the one that isn't sealed to one of my speaker cables and they look pretty similar... what should the main differences be...

I thought it would be an issue so thats why we didnt bother trying to guess.

[Lifeofsobriety]

Haha quick update

So we are definitely noobs.. the other day i took another look at these two cables.... and they are labled... in little white letters on the side of the cable haha thanks anyways

[kennydoe]

a tip for the next time, or if you come across unlabeled cables...

PAY ATTENTION!

You'll have to unscrew the plug and look...

Instrument cables have braided wire around the outside of a single shielded wire

Speaker cables have two shielded wires and no braided wire.

It's not a great idea to substitute one for the other. That being said, an instrument cable will work 'ok' as a speaker cable in a moment of need, but a speaker cable will sound horrendous plugged into an instrument (especially a guitar)

[Lifeofsobriety]

Originally Posted by adamcbest

the amp's output transformer will burn up!! big difference between the cables. never use an instrument cable as a speaker cable. although i think you can use a speaker cable as an instrument without harming anything.

So is that not right?

Thanks for the info on how to tell the difference though... that will be helpful.

[David McCarroll]

Originally Posted by kennydoe

It's not a great idea to substitute one for the other. That being said, an instrument cable will work 'ok' as a speaker cable in a moment of need, but a speaker cable will sound horrendous plugged into an instrument (especially a guitar)

No, don't do this! An amp of high enough wattage will heat the instrument cable to the point where the insulation between hot and shield could physically melt, shorting the output of your amp, which, unless it has speaker fuse protection (and even with if you are unlucky), will short out your output transformer and blow it up! That's the LEAST that might go wrong - and rewinding/replacing transformers is about the most expensive repair you'll ever do to an amp!

The opposite way around (using a sspeaker cable as a guitar lead) will work, will not risk anything, but it will be an unshielded cable and you will get a lot more noise.

[MadRyan]

I use Canare speaker cable which is pretty big so it's easy to tell. I also use either Mogami or Canare instrument cable which tends to be on the small side, so again, easy to tell.

[Vim Fuego]

Originally Posted by David McCarroll

No, don't do this! An amp of high enough wattage will heat the instrument cable to the point where the insulation between hot and shield could physically melt, shorting the output of your amp, which, unless it has speaker fuse protection (and even with if you are unlucky), will short out your output transformer and blow it up! That's the LEAST that might go wrong - and rewinding/replacing transformers is about the most expensive repair you'll ever do to an amp!

The opposite way around (using a sspeaker cable as a guitar lead) will work, will not risk anything, but it will be an unshielded cable and you will get a lot more noise.

Just to give you the figures,
Power = Current^2 * Resistance
So for a 100 Watt amp into 8 Ohm cabs
100 = Current^2 * 8
12.5 = Current^2
sqrt(12.5) = Current
3.6 Amps = Current
Guitar Cables *WILL NOT* handle 3.6 Amps!
Aways use speaker cables for speakers!
If you make your own up, use cable that can handle the current (not 3 Amp cable)
Jim
(^2 means "squared")

[Lifeofsobriety]

Originally Posted by MadRyan

I use Canare speaker cable which is pretty big so it's easy to tell. I also use either Mogami or Canare instrument cable which tends to be on the small side, so again, easy to tell.

My speaker cable is a beast too haha its like 5 times thicker than any of my other cables so i have never thought about this before.

It seemed like it would be a bad idea to use an instrument cable for an amp because of that very reason so I'm glad i didn't.

Thanks